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Diffstat (limited to 'date-fns/src/setMonth/index.ts')
-rw-r--r-- | date-fns/src/setMonth/index.ts | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/date-fns/src/setMonth/index.ts b/date-fns/src/setMonth/index.ts new file mode 100644 index 0000000..c625378 --- /dev/null +++ b/date-fns/src/setMonth/index.ts @@ -0,0 +1,44 @@ +import toInteger from '../_lib/toInteger/index' +import toDate from '../toDate/index' +import getDaysInMonth from '../getDaysInMonth/index' +import requiredArgs from '../_lib/requiredArgs/index' + +/** + * @name setMonth + * @category Month Helpers + * @summary Set the month to the given date. + * + * @description + * Set the month to the given date. + * + * ### v2.0.0 breaking changes: + * + * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes). + * + * @param {Date|Number} date - the date to be changed + * @param {Number} month - the month of the new date + * @returns {Date} the new date with the month set + * @throws {TypeError} 2 arguments required + * + * @example + * // Set February to 1 September 2014: + * const result = setMonth(new Date(2014, 8, 1), 1) + * //=> Sat Feb 01 2014 00:00:00 + */ +export default function setMonth(dirtyDate: Date | number, dirtyMonth: number): Date { + requiredArgs(2, arguments) + + const date = toDate(dirtyDate) + const month = toInteger(dirtyMonth) + const year = date.getFullYear() + const day = date.getDate() + + const dateWithDesiredMonth = new Date(0) + dateWithDesiredMonth.setFullYear(year, month, 15) + dateWithDesiredMonth.setHours(0, 0, 0, 0) + const daysInMonth = getDaysInMonth(dateWithDesiredMonth) + // Set the last day of the new month + // if the original date was the last day of the longer month + date.setMonth(month, Math.min(day, daysInMonth)) + return date +} |